Highly ductile anchors with adaptive stiffness for timber construction
The patented Duktiplex anchoring element developed by BFH and Ancotech AG exhibits highly ductile behaviour and adaptive stiffness and permits the efficient implementation of earthquake protection measures on timber structures.
- Lead school School of Architecture, Wood and Civil Engineering
- Institute Institute for Timber Construction IHB
- Research unit Timber Structures group FGH
- Funding organisation Innosuisse
- Duration 01.09.2018 - 08.01.2024
- Project management Prof. Dr. Cornelius Oesterlee
- Head of project Prof. Martin Geiser
- Partner Ancotech AG
- Keywords Timber construction; Earthquake protection
The development of a reliable, simple and cost-effective anchoring system is a major step towards ensuring the efficient implementation of earthquake protection measures in timber-framed buildings. With the trend towards ever bigger and taller timber structures and as there is often little space for bracing elements in modern architecture, the standard anchors currently available on the market are often inadequate. Engineers then have to design and calculate special anchoring solutions. The fact that anchors are installed at the point where concrete and wood meet – involving collaboration between structural engineers and timber engineers, bricklayers and joiners – makes the situation all the more complex. This means the anchoring of modern timber structures is very time-consuming – not just in terms of implementation, but also planning. In response, BFH and Ancotech AG launched an Innosuisse project in 2018 to develop tensile anchoring elements for forces in the medium to high range.
Course of action
BFH and Ancotech AG are collaborating on the development of earthquake-resistant anchoring systems. The first project goal is developing a non-ductile solution for timber-framed and CLT buildings in the higher force range, a requirement not met by the systems currently available on the market, i.e. above around 50–70 kN. The project’s second objective is to develop a highly ductile anchoring element to enable the efficient implementation of capacity calculation in timber construction.
This new anchoring element is currently still under development. Testing of practical implementation on real-world structures will begin soon. Special attention is being paid to the issue of vertical movement of the ductile wall. Regardless of whether or not the bracing wall is load-bearing, the forces must be transferred between the horizontal sections and the walls. The anchoring system’s low rigidity in the event of an earthquake means the deformation caused is significant which has a positive effect on supporting structure ductility and enables high behaviour coefficients to be achieved. A solution will be proposed for efficient implementation of capacity calculations in timber construction.